Internal-combustion engine.



T, F. FLINN.

iNTERNAL CGMBUSTION ENGINE,

APPLICATION FILED FEB.15.19!7.

Patented Dec. 17', 1918.

2 SHEETS-SHEET l.

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NTERNAL COMBUSTION ENGNE.

APPLICATION man FEB.15.1911.

aented Dec. 17, 1918.

2 SHEETS-SHEET 2.

THOMAS F. FLINN, OF BROOKLYN, NEW YORK.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Application led February 15, 1917. Serial No. 148,723,

To all ywhom z't may concern:

Be it known that I, THOMAS F. FLINN, a citizen of the United States, residing at 72 Second Place, Brooklyn, New York, have invented a new and useful Improvement in Internal-Combustion Engines, of which the following is a specification.

rIhe main object of my invention is the organization of the parts of a reciprocating internal combustion engine to reduce shock and eliminate the transmission thereof to the engine bed and to the suppoit upon whiih itis carried, the attainment of this object being particularly desirable in aeroplane engines and it is for such use that my invention is specially adapted, but obviously the saine object is also of great importance in engines designed for .other work and therefore I do not limit the application of my invention to aeroplane use.

For aeroplane power plants, it is desirable that the engine' be balanced not only for mass but also dynamically in order to prevent tlie transmission of the shock resulting from the change in direction of motion of the piston and its connecting rod and appurtenant parts, and it is also desirable that the engine be of light weight per delivered horse-power with low piston speed and relatively large cubical displa^ement. To secure these objects, I so arrange the engine parts that the energy of the exploding charge is counterbalanced against the work to be done in compressing the charge, in such manner as to produ'e strains on the crank shaft whifh are substantially equal and opposite in direction and exerted thereon at points 180 apart so that the crank shaft is largely relieved of lateral distortion and its bearings and the engine bed supporting the same are not called upon to sustain the shock incident to the reversal of direction of the reciprocating. mass or to withstand any strain other than that due to the angle of the connecting rods which, is slight.

The preferred embodiment of my invention includes four cylinders in double opposed relation all rigidly connected and mounted to reciprocate on a suitable bed and preferably in unison, two of such cylinders being disposed on each side of the crank shaft and the cylinders on each side being preferably in alinment with those of another. The four pistons within these cylinders are also rigidly yoked together and the crank shaft cranks are 180 apart, those on one side being connected to the set of pistons and those on the other to the set of cylinders. By virtue of this arrangement it will be observed that the pistons are caused to travel one-half the stroke and the cylinders the other half so that the range of stroke movement for any given part is reduced by one-half as compared to ordinary engine designs, and each explosion, exerting an equal pressure on the piston and cylinder head thus exerts an equal pressure on the oppositely arranged cranks connected therewith so that a alancin of the pressures takes place in the cran shaft as above stated without transmission of shock to the crank shaft` bearings, bed or crank case. The crank shaft for four cylinders thus arranged is shorter than commonly employed in well balanced four cylinder engines and 1s therefore of less mass and the less subje;t to torsional vibration. The shorter radius of the cranks relative to the cubical displacement also permits them to be of low weight and all of these parts are adequately supported on a bed which may be relatively very light compared to conventional engine designs, because it does not sustain the shock of compression and explosion.

In addition to the advantages above briefly alluded to, the invention also involves numerous other important features which will be ome apparent to those skilled in the art from the following description of the preferred form which has beentaken in illustration of the principles involved.

In the accompanying drawings forming part of this application, and showing said preferred form:

Figure l is a top plan view more or less diagrammatic of an engine constructed in accordance with my invention, certain parts being broken away;

Fig. 2 is a vertical longitudinal section 'on the line II-II of Fig. l;

Fig. 3 is an end view;

Fig. 4 is a transverse section on the line IV-IV of Fig. 1; and

Fig. 5 is a top plan view of a portion of the piston conne ting mezhanism.

In the specific form illustrated, four cylinders 10, 11, 12 and 13 are disposed with their axes in the same plane and in pairs upon opposite sides of a crank shaft 14. The two cylinders 10 and 11, which Patented Dec. 17, 1918.

rigidly united in any suitable manner as,

for instance, by the connection block 15 and a similar block unites the two cylinders 12 and 13 which are also paralleland arranged side by side. The two cylinders 10 and 11 are rigidly connected to the two cylinders' 1.2 and 13 on the opposite side of the crank shaft by suitable means such for instance, as the set of rigid tie-rods 16 or any equivalent connecting structure.

Within each cylinder is any suitable form of piston 17 adapted for internal combuss tion engine use. Such parts as packing rings and the like, which are common in engine construction but which form no portion of my invention, have not been illustrated. rlhe four pistons are rigidly connected so that they move in unison in their respective cylinders. rllhis connecting mechanism may be varied within wide limits. ln Fig. 2, the crank shaft 141 has a long crank pin 18 connected to the two pistons in the cylinders 12 and 13 by connecting rods 19- whereby the two pistons therein receive simultaneous and equal movements. These pistons are connected to the pistons in. the opposite alined cylinders by means not interfering with the throw of the vpiston crank 18, ,and consisting of frames each including a yoke 20 surrounding the crank and connected by a rod 21 with the piston ii the alined cylinder. f

rlhe connecting rods 19 and the single crank 18, to Vwhich they are connected, may be relied on as the sole means for holding all four pistons rigid in respect to each other, but, vadditional connection may be employed where necessary or advisable, such as thevcross brace 22 secured to the rods 21 as shown only in Fig. 5.

The connection of the united cylinders to the crank shaft is made by two separate connecting rods 23 to cranks on opposite sides of the piston crank 18, which cranks both extend in the same direction and at an angle of 180 to said crank 18. As illustrated, these connecting rods are joined to the trunnions or pivot pins 24 projecting outwardly from diametrically opposite sides orn the cylinders lO'and 11 and held rigid in respect to said cylinders in any suitable manner as, for instance, by brackets 25. it will ofcourse'be understood that the said trunnions may be attached to the cylinders in various ways suitable for the purpose and it will'be evident that other means might be employed to give the simultaneous and opposite movement of the opposed cylinders and pistons.

It will be noted that the connecting rods 19 extend to the pistons at one side of the crank shaft while the connecting rods 23 extend tothe cylinders upon the opposite side or the crank shaft, which arrangement mannen is .desirable in that one pair of connecting rods and their pivotal connections tend to balance the other pair although, so far as the actual operating of the engine is contheir cranks should be approximately equal to the stroke of the pistons.

As the cranks for the cylinders extend diametrically opposite to the cranks for the pistons, and as all of the pistons are rigidly connected and all of the cylinders are rigidly connected, it will be apparent that any rotation of the lcrank shait eiiects a movement of all of the pistons 'in' one direction and a corresponding and equal movement of all oi' the cylinders in the opposite direction. As these cylinders can approkimately counter-balance the weight of the pistons, it will be noted that the shifting of the'centers of mass of the pistons and cylinders toward or from each other, does not materially shift the center of mass of the engine as a whole, and it will also be noted as above stated that the pistons and cylinders each travel only one-half the length of a complete piston stroke and that the oscillation amplitude ci the connecting rods is only one-half of what it would be with the cylinders stationary and the full stroke performed by the piston. Thus, the bearings of the crank shaft have to sustain but very slight load and resist but slight shock or fiar.

As the combustion chambers in two adjacent cylinders are increasing in size while the chambers in the alined cylinders'are de-` creasing in size, the valves may be so timed for a tour-cycle engine that an explosion will take place for every stroke, and compression'will take place in a cylinder at one side oit the crank shaft during the explosion or power stroke in a cylinder on the opposite side of the crank shaft. Thus, the endwise movements ot the cylinders and pistons resulting from every explosion operate to compress a charge in a cylinder at the other` side of the crank shaft. The increasing resistance encountered as the compression of a charge increases in one cylinder, cushions the movement resulting from the' explosion in another cylinder and` therefore every explosion stroke and every reciprocating movement is partly cushioned.

Various means may be employed for delivering the charge to and conducting the exhaust gas from the several cylinders, ignit-ing the charges at the proper time, and insuring the proper cooling oi the cylinders. l'n the drawings, 1 have illustrated means for peorniing these various operations,

and this mechanism illustrated possesses certain advantages but I Wish it understood that various other means or mechanisms might be vemployed for performing these operations Without departing from the broad scope of my invention as defined in the appended claims.

For cooling the cylinders, I have illustrated Water jackets 26, one for each cylinder. These Water jackets may, if desired. be formed as parts of the cylinders and provided With flexible or telescoping connections for the supply and exhaust of cooling Water, or air cooling may be utilized by applying radiating fins or flanges to the cylinders as will be understood. As illustrated, however the Water jackets are stationary and form slideways for the cylinders being connected in pairswith a water inlet and a water outlet connection for each pair. The jacket constructlon comprises tvvol cylindrical shells rigidly connected,

spaced and sealed at their ends and rigidly mounted on the frame or base of the engine. rlhe inner shell closely lits its cylinder and is to be understood as amply lubricated so that the heat from the cylinder may be readily absorbed by the Water jacket. Manifestly, other means. may be employed for supporting the cylinders and will be particularly necessary if the cylinders are air cooled.

For igniting the charge, each cylider i may be provided, preferably in its head,

with a spark plug or any other suitable form of igniting means 29. Theelectric connections to the igniter may be made flexible, telescoping, or otherwise,'whereby the delivery of `current will not be affected by the reciprocation of the cylinder. As shown, particularly in Fig. 2, the igniter plug has a current conducting rod 30 secured to it and mounted torride on an insulated roller or other contact member 31 mounted on the stationary water jacket and connected to any suitable ignil-ion system.

For admitting the charge mixture, or fuel to the engine cylinders and discharging the exhaust, I may employ the valve mechanism and conduit connections illustrated, which may of course be varied in detail or replaced by any equivalent means according to the design of engine. The valve gear illustrated adapts the engine to operate' on a four-stroke cycle, yet by obvious change the engine would be two-stroke cycle if desired.

The valve chambers 32 and 33 are shown as extending in the general direction of the `to the crank shaft Varies.

carried by the reciprocating cylinder in each case.

For operating these levers and properly timing the opening and closing of the valves, I mount a cam shaft 38 in a suitable bearing sleeve 40 rigidly secured to the cylinders. The bearings (Fig. 2) are rigidly connected to the cross rods 16 or other means which hold the cylinders rigid in respect to each other. The cam shaft extends transversely of the cylinders and is parallel to the crank shaft, but as it is moved bodily with the cylinders, its relationship The supporting bearing 40 of the cam shaft has bracket extensions 41 serving to guide and support push rods 42. These rods are each connected to a corresponding valvevoperating lever 36, and their inner ends are equipped with rollers engaging the cams '39 on the shaft so that as the cam shaft rotates, the rods are pushed endwise to open the valves in the proper sequence. "When cylinder 10 is firing, cylinder 12 may be compressing, cylinder 11 may be taking in charge and cylinder 13 exhausting. At the end of the stroke, cylinder 12 lires, cylinder 13 takes in charge, c linder 11 compresses and cylinder' 10 ex austs. A compression at one side of the crank shaft is thus counter-balanced against the firing in a cylinder at the opposite side.

The cam shaft is geared tWo-to-one to the crank shaft as common in four-cycle engine construction, but as the cam shaft moves back and forth with the cylinders, it is evident that special gearing is necessary to vinsure this continuous rotation of the caml shaft at the proper speed. Merely as an example of such a mechanism, I have illustrated the crank shaft as provided with a helical pinion 43 meshing with a helical gear 44 of twice the diameter mounted on a counter shaft 45 Which extends lengthwise of the engine and is journaled on the engine bed. A bevel pinion 46 splined and sliding on the shaft and maintained in mesh with a bevel pinion 47 on the cam shaft constitutes the drive for the latter. The cross bar 48, rigidly connected to the cylinders 10 and 11 holds the sliding pinion 46. in its bearing 49. Thus, as the cylinders reciprocate, they carry with them not only the cam shaft 38, but also the pinion 46 through which the valves are properly operated.

For delivering the charge to the casings of the inlet valves, any suitable iiexible, telescoping or other connection may be employed. Merely as an example of such, I have shown the inlet valve cages 33 each connected to and carrying a conduit 50 which has a portion parallel to the direction of movement of the cylinders and telescoping Within a conduit 51 which may be stationary and connected to the carbureter or other source ci* fuel or explosive mixture. The movement of the cylinders and the conduits 50 back and forth will not vary the uniform delivery of fluid to the conduit 5l as the pulling out oi a conduit 5() at one end 1s accompanied by an inward movement of the opposite conduit 50. A similar arrangement may be employed for the valve cages of the outlet valves, particularly ir it is desired to employ a single muliier, but for aeroplane work and for certain other uses, the outlets from the valve cages 33 may discharge directly into the air as is indicated particularly at the left hand end of Fig. 2 and in Fig. 3.

The engine bed may be of any suitable construction forming a support for the crank shaft bearings and the guides or slideways `for the cylinders and because or the cushioned and balanced operation an extremely light bed is entirely suitable.

.Having thus described my invention, what v l claim as new and desire to secure by Letters Patent is:

l. ln combination, a crank shaft, two pairs of cylinders disposed' on opposite sides thereot and all rigidly connected, rigidly connected pistons in said cylinders, and connections between said cylinders, vpistons and crank shai't for reciprocating said pistons in one direction and reciprocating said cylinders in the opposite direction.

2. ln combination, a crank shalt having oppositely disposed cranks or equal throw, a pair of cylinders disposed upon one side of said shaft, a second pair of cylinders disposed on the opposite side of said shaft, means for rigidly connecting all of said cylinders together, separate pistons in said cylinders, means for rigidly connecting all of said pistons together, connections between said cylinders and one of said cranks, and connections between said pistons and the other of said cranks, whereby upon the rotation of said crank shaft, said pistons and cylinders are caused to simultaneously reciprocate equal distances in opposite directions. i

3. An internal combustion engine having a crank shaft, two pairs of cylinders, the pairs being disposed on opposite sides of' said shaft, pistons in said cylinders, connections between said cylinders, pistons and crank shaft for simultaneously reciprocating all of said pistons in one direction and all of said cylinders in opposite directions, and valve mechanism so timed that power and intake strokes in the cylinders ot one pair occur simultaneously with exhaust and compression strokes in the cylinders of the other pair.

An internal combustion engine having a crank shaft, two cylinders disposed on one side of said crankshaft, two cylinders disposed on the opposite side thereof, connecneef/,eer

tions. between said cylinders and said shal tor-simultaneously moving all of said cylinders endwise upon a rotation of said shaft, separate pistons in said cylinders, connections between said pistons and said crank shaft for moving said pistons in a direction opposite to the direction of movemtnt of said cylinders upon the rotation of said crank shaft, and means for exploding the charge lirst in a cylinder at one side of said crank shaft and then in a cylinder at the opposite side of said crank shaft.

5. An internal combustion engine having four cylinders'arranged in pairs, the two cylinders of one pair being in alinement with the two cylinders of the other'pair, pistons within said cylinders, a crank shaft having cranks extending in diametrically opposite directions, connections between one of said cranks and all of said cylinders, connections between the other or" said cranks and all of said pistons, valve mechanism for said cylinders, and means for supplying fuel to said valve mechanism, said Valve mechanism being so timed that the compression ci a charge in one cylinder cushions the endwise movement of said cylinders and pistons at the end of a power stroke in another cylinder.

6. ln combination, a crank shaft, two pairs of cylinders disposed upon opposite sides thereof, supports for said cylinders permitting of their endwise sliding movement, means for rigidly connecting all of said cylinders together, pistons in said cylinders, a rigid connection between each piston and the piston of the alined cylinder, a pair of cranks 180O apart on said crank shaft, connections between the cylinders of one adjacent pair of cylinders and one or said cranks, and connections between one piston of each alined pair of pistons and the other crank.

7. An internal combustion engine, including tour rigidly connected cylinders arranged in pairs, the cylinders of one pair being in alinement with those of the other, four rigidly connected pistons within said cylinders, and means for reciprocating said cylinders and pistons simultaneously and to equal distances in opposite directions.

8. An internal combustion engine, including four rigidly connected cylinders arranged in pairs, the cylinders of one pair being in alinement with those of the other, four rigidly connected pistons within said cylinders, means for reciprocating said cylinders and pistons simultaneously and to equal distances in opposite directions, valve mechanism, and means for controlling said mechanism to eiect compression and exhaust strokes in the cylinders oi one pair during the power and intake strokes in the cylinders orn the other pair..

9. An internal combustion engine, including four rigidly connected cylinders arranged in pairs, the cylinders of one pair being in alinement vwith those of the other, four rigidly connected pistons within said cylinders, means for reciprocating said cylinders and pistons simultaneously and to equal distances in opposite directions, a cam shaft, bearing rigid with said cylinders and bodily movable therewith for supporting said cam shaft, gearing for rotating said cam shaft, and valve mechanism for said cylinders controlled by the rotation of said cam shaft.

10. An internal combustion engine, including four rigidly connected cylinders arranged in pairs, the cylinders of one pair being in alinement with those of the other, four rigidly connected pistons within said cylinders, means for reciprocating said cylinders and pistons simultaneously and to equal distances in opposite directions, a stationary conduit for supplying explosive charge, and connections between said conduit and said reciprocatory cylinders,

11. An internal combustion engine, includin four rigidly connected cylinders arrange in pairs, the cylinders of one pair being in alinement with those of the other four rigidly connected pistons within said cylinders, means for reclprocating said cylinders and pistons simultaneously and to equal distances in opposite directions, valves carried by said cylinders, a cam shaft carried thereby, operative connections between said cam shafts and said valves, and means for continuously and uniformly rotating said cam shaft during the bodily -movement of said cam shaft lback and forth with said cylinders.

12. An internal combustion engine, including four rigidly connected cylinders arranged in pairs, the cylinders of one pair being in alinement with those of the other, four rigidly connected pistons within said cylinders, means for reciprocating said cylinders and pistons simultaneously and to equal distances in opposite directions, valve mechanism for said cylinders, valve operating rods extending lengthwise of said cylinders, and means for actuatin said rods during the reciprocation of sald cylinders to control the operation of said valve mechanism.

13. An internal combustion4 engine, in-

cluding four rigidly connected cylinders arranged in pairs, the cylinders of one pairV being in alinement with those of the other, four rigidly connected pistons within said cylinders, means for reclprocating said cylinders and pistons simultaneously and to equal distances in opposite directions, and stationary water 'jackets within which said cylinders reciprocate.

14. An internal com'bustion engine, including a cylinder, a piston therein, a crank shaft havin separate cranks of opposite and equal throw, separate connections between said cranks and said cylinderpand piston for simultaneously reciprocating the cylinder and piston in opposite directions, a cam shaft carried by said cylinder, valve mechanism operated by said cam shaft, and means for transmitting power from said crank shaft to said cam shaft.

l5. An internal combustion engine, includin a cylinder, a piston therein, means including a crank shaft for simultaneously reciprocating the cylinder and piston in straight lines in opposite directions, a cam shaft carried by said cylinder, valve mechanism operated by said cam shaft, and gearing for transmitting power from said crank shaft to said cam shaft.

16. An internal combustion engine, including a cylinder a piston therein puppet valves for said cy inder, means inc uding a crank shaft for simultaneously reciprocating the cylinder and piston in straight lines in opposite directions, valve operating rods, extending len hwise of said cylinder, a cam shaft carried y said cylinder for operating said valve rods, and gearing for transmit` ting power from said crank shaft to said bodily movable cam shaft. y

17. An internal combustion engine, including a cylinder, a piston therein, a crank shaft having separate cranks connected to said cylinder and piston for simultaneously reciprocating the cylinder and piston in opposite directions, a cam shaft carried by said cylinder, valve mechanism operated by said cam shaft, and gearing including a sliding connectionfor rotating said cam shaft from said crank shaft at one half the speed of the latter.

In testimony whereof I have signed this specification.

THOMAS r. FLINN, 

